Wednesday, July 04, 2007


HGB Area

 

Maximum 1-hr Ozone (ppb)

Maximum 8-hr Ozone (ppb)

AQF F1

31 C96

-

Statistical Model

49.6

-

Human Forecast

36

-

Acutal (Observed)

37 C1034

-

 

DISCUSSION

Same weather pattern has lasted for two weeks - cloudy and S/SE wind. Today's wide spread shower will depress
ozone production to a low of 10-20 ppb at max location. Adding 10-20 background ozone, regional ozone is
likely to be in the 20s, with high in the 30s. Stat model does not account the wide-spread shower, so it is
most certain to overpredict. High ozone spot shall remain in the Kingwood area.

Yesterday's sky is overcast most of the time, with little rain falling. Generally, an overcast sky foretells
a low ozone production. However, an overcast sky with no rain means that the cloud is not thick and sunlight
can penetrate occasionally. Given a low mixing height, ozone level can rise more than expected.

From NWS

500mb low over south central texas will move slowly southward today as 1000-500mb relative humidity remains
high across the eastern two-thirds of the state this afternoon. with precipitable water values between 2.0
and 2.25 inches across south tx...the threat of heavy rainfall continues for the cwa as areas of convection
are expected to develop across the coastal sections this morning and move inland. satellite and radar images
indicate convection developing across extreme southwest portions of southeast tx early this morning...as the
area of showers and thunderstorms over extreme east tx extending southward into the gulf of mexico lifts
northward. believe mcs over northeast mexico will continue to weaken this morning allowing inflow over the
western gulf to shift towards the coastal bend where new convection is developing. doppler radar is
estimating rainfall rates of 1 to 2 inches per hour with the convection offshore the upper tx coast. will
likely see 1 to 2 inches of rainfall across the cwa today with higher amounts of 3 to 4 inches where training
of cells develops. rain chances look likely again today even though most of the area saw very little in the
way of rainfall yesterday. 00z gfs appears to be suffering from convective feedback so will lean more towards
the 00z nam for pops. also...the mav mos temperature guidance looks too cool for today so will also lean
towards the met mos for highs this afternoon. flood watch for southeast tx was expanded and extended through
this afternoon yesterday so will continue with the ffa as is for now.

7/4/2007 11:00:04 AM